Active ingredient

Isoflupredone acetate for Animals: Mechanism, Doses by Species & Brands

Reviewed by Dr. Ravi Baraiya, B.V.Sc.Updated 2 Nov 20262 sources

Isoflupredone is a glucocorticoid used in cattle for primary ketosis and in cattle, horses and pigs for inflammatory conditions (Predef 2X, 2 mg/mL) ^[2]. Unlike most synthetic steroids it also has strong mineralocorticoid effects and raises the risk of severe hypokalaemia ^[1].

Drug class: Corticosteroid (glucocorticoid with mineralocorticoid activity)
Sourced doses for: Cattle, Horses, Pigs
Brands on this site: Predef 2X

Isoflupredone acetate dose calculator

Type the strength printed on your own product. Results are calculated in your browser from the cited doses on this page — always check the label of the product you use.

Isoflupredone acetate dose by species

Species	Use	Dose	Route	How often	Basis
Cattle	Ketosis and inflammatory conditions	10–20 mg/animal^[2]	IM	May be repeated in 12–24 hours	Label
Horses	Inflammatory conditions	5–20 mg/animal^[2]	IM	Repeated as necessary	Label
Pigs	Inflammatory conditions Label: 5 mg for a 300 lb (about 136 kg) pig.	5 mg/animal^[2]	IM		Label

What isoflupredone acetate is used for

Cattle: primary bovine ketosis; supportive therapy in parturient paresis ^[2].
Cattle, horses and pigs: musculoskeletal and allergic conditions (Predef 2X) ^[2].

How isoflupredone acetate works (mechanism of action)

Glucocorticoids bind receptors in the cell cytoplasm and the hormone–receptor complex changes which proteins the cell makes; one of these, lipocortin, inhibits phospholipase A2, the first step of prostaglandin and leukotriene production ^[1]. Isoflupredone lacks selectivity for glucocorticoid over mineralocorticoid effects ^[1].

Safety, contraindications and precautions

Increases the risk of severe hypokalaemia — stop treatment if signs appear ^[1]^[2].
May induce the first stage of parturition in the last trimester of pregnancy ^[2].
Do not use in calves to be processed for veal or in horses intended for human consumption ^[2].

Withdrawal periods

Withdrawal periods belong to a product and a country — the rows below name the product they come from. Always follow the label of the product you use.

Species	Product	Withdrawal	Detail
Cattle	Meat	7 days	Predef 2X (US): not slaughtered within 7 days of the last treatment.^[2]
Pigs	Meat	7 days	Predef 2X (US): not slaughtered within 7 days of the last treatment.^[2]

Brands that contain isoflupredone acetate

Brand	Company	Contains	Market
Predef 2X	Zoetis	Isoflupredone acetate	USA (FDA label)

Frequently asked questions

Why can isoflupredone cause low potassium?

It has strong mineralocorticoid activity, which increases the risk of severe hypokalaemia ^[1].

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Medically reviewed by

Dr. Ravi Baraiya, B.V.Sc.

Veterinarian · Reviewed 2 Nov 2026

References

Corticosteroids in AnimalsMerck Veterinary Manual · 2024 · Veterinary reference
Passage read from this source
Glucocorticoid-specific receptors in the cell cytoplasm bind with steroid ligands to form hormone-receptor complexes
Such proteins include lipocortin, a protein known to inhibit PLA2alpha
but lacks selectivity for mineralocorticoid effects and increases the risk of severe hypokalemia.
PREDEF 2X (isoflupredone acetate) — labelDrugs.com Vet — US label text, Zoetis · 2026 · Product label
Passage read from this source
Each mL of PREDEF 2X contains 2 mg of isoflupredone acetate; also 4.5 mg sodium citrate hydrous;
is an effective and valuable treatment for the endocrine and metabolic imbalance of primary bovine ketosis.
The usual intramuscular dose for cattle is 10 to 20 mg, according to the size of the animal and severity of the condition.
This dose may be repeated in 12 to 24 hours if indicated.

For veterinary professionals. Information supports — never replaces — clinical judgement; always check the current product label and local regulations.